What Windows app is this phone dialogue box for?

Recently I have been very very anxious to get my android phone set up so I can make/take calls and take care of my text messaging through my Laptop. Messaging for web (google) is nice, but there's no notifications, and you can't make/take calls. I pursued the "Your Phone" app for windows and android, but that was an absolute nightmare. It took 20 tries (no exaggeration) to "pair" my phone. Then when I did, the app still said it couldn't connect to the phone to make calls. I barely got the messaging aspect to work for about 20mins, but some of the conversations were missing as much as 24hrs worth of texts. Other were perfectly up to date. Closing the app just started the nightmare all over again, often requiring that I restart my phone and PC, or worse, uninstall the apps (though Powershell on Windows) and reinstall them, only so they could still not work. In the end I uninstalled the "Your Phone" app completely from both devices and have said "Forget it!".
Today I received a call from a friend, and while on the call with him I disconnected my laptop from it's dock and the attached image came up, and at that same moment, the audio for the call went from my BT headphones to my Android phone. My friend had to go before I got a chance to open Task manager to figure out what this is.
The only two ways Im aware that phone and Laptop are linked are by Bose headphones, which I have connected to both devices simultaneously and by Bluetooth, which the phone is listed under "Other Devices".
Does anyone know what App this dialogue box is associated with? I want to open it again so that I can play around with it, see if maybe this is a hidden lesser known way of making/taking calls with Windows 10. I want so very badly to get all phone and messaging through the laptop while Im working.


Wind 10 - Ver 1903 (OS Build 18362.657)